#NAME

App::cpm - a fast CPAN module installer

#SYNOPSIS

> cpm install Module

#DESCRIPTION

cpm is a fast CPAN module installer, which uses Menlo in parallel.

Moreover cpm keeps the each builds of distributions in your home directory, and reuses them later. That is, if prebuilts are available, cpm never builds distributions again, just copies the prebuilts into an appropriate directory. This is (of course!) inspired by Carmel.

For tutorial, check out App::cpm::Tutorial.

#MOTIVATION

Why do we need a new CPAN client?

I used cpanm a lot, and it's totally awesome.

But if your Perl project has hundreds of CPAN module dependencies, then it takes quite a lot of time to install them.

So my motivation is simple: I want to install CPAN modules as fast as possible.

#HOW FAST?

Just an example:

> time cpanm -nq -Lextlib Plack
real 0m47.705s

> time cpm install Plack
real 0m16.629s

This shows cpm is 3x faster than cpanm.

#CAVEATS

eserte reported that the parallel feature of cpm yielded a new type of failure for CPAN module installation. That is, if ModuleA implicitly requires ModuleB in configure/build phase, and ModuleB is about to be installed, then it may happen that the installation of ModuleA fails.

I can say that it hardly happens especially if you use a new Perl. Moreover, for a workaround, cpm automatically retries the installation if it fails.

I hope that if almost all CPAN modules are distributed with static install enabled, then cpm will parallelize the installation for these CPAN modules safely and we can eliminate this new type of failure completely.